#include<iostream>
#include<algorithm>
#include<string>
#include<vector>
#include<queue>
#include<functional>
#include<cmath>
using namespace std;
int a, b;
int main() {
	scanf("%02d:%02d", &a, &b);
	int c = (a * 60 + b + 5) % 1440;
	printf("%02d:%02d\n", c / 60, c % 60);
	return 0;
}